Dropdown list problem when my mobile web application opened in android phone

See more:

C#

Javascript

My dropdownlist has onchangeevent (handled in javascript(clientside)). This generally fires when we change the value in the dropdown (different value). But when I open my mobile web application in andriod phone, it is firing when I change the same value again. I have explained my scenario below:

Scenario:

Dropdown list for years:

1) For example when I select 2011 as year - onchangeevent is occured.
2) If i change the value to 2011 again then also onchangeevent(javascript) is fired.

This generally does not happen in normal browsers.

Please do the needful.